1 / 17

基本粒子

基本粒子. The Periodic Table. Mendeleev (1869) introduced the periodic table. 2. Discovery of Electron. J.J. Thomson found that Cathode rays are electrons. O’ 狹縫. C. B. O 陰極. C’. E. A 陽極. CC’ 平行面板. 圖一. Pluecher (Germany) found cathode rays in 1858

javan
Télécharger la présentation

基本粒子

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 基本粒子

  2. The Periodic Table Mendeleev (1869) introduced the periodic table 2

  3. Discovery of Electron J.J. Thomson found that Cathode rays are electrons O’狹縫 C B O陰極 C’ E A陽極 CC’平行面板 圖一 Pluecher (Germany) found cathode rays in 1858 1870s Crookes (British) studied this extensively ·all metals ·-charge turn in magnetic field Like X-rays (Hertz, etc.) ·unaffected by e-field· can penetrate Al foil 3

  4. The Structure of Atoms Rutherford (1912) showed that atoms contain a central nucleus Electrons orbit nucleus with well-defined energy and ill-defined positions 10-10m 4

  5. The Structure of Nuclei 10-15 m J. Chadwick (1932) discovered neutron 2α4 + 4Be9  6 C12 + 0n1 Nucleus contains protons with charge +e and uncharged neutrons 5

  6. The Structure of Nucleons Neutrons and protons contain quarks “Seen” in the deep inelatstic ep scattering at SLAC (1967) 10-15m 6

  7. The Constituents of Matter charge quarks electron u e 2 3 e + 1 3 e - d -e Protons contain uud - charge = +e Neutrons contain udd - charge = 0 7

  8. Proton Decay? Super- Kamiokande experiment is 1,000 m underground in Mozumi Mine 11000 photomultiplier tubes Cherenkov radiation 50000 tons pure water • τp>1035 years (Experiment) • τp~1036 years (GUT theory) 8

  9. Prediction of Antimatter Paul Dirac predicted existence of the positron in 1928 Dirac’s equation implies: positron mass = electron mass positron charge = +e 9

  10. Discovery of Antimatter Anderson (1932) discovered the positron predicted by Dirac 10

  11. Production of e+e- Pairs e e - + High energy g-ray becomes an electron-positron pair E = mc2 11

  12. Antimatter Disappears in a Matter Dominant World e e + - Inverse process also occurs, electrons and positrons annihilate to produce photons (energy) E = mc2 12

  13. The Fundamental Particles ne nm nt c t u 1956 1963 1976 1995 e m t s b d 1895 1936 1973 1978 1947 six leptons six quarks Spin ½ fermions Along with their anti-particle partners 13

  14. Basic Interactions 14

  15. A Colorless World Quarks Leptons Charge=+2/3 ΛBaryon u c t πMeson Mesons: π,ρ,Φ,k,B… Baryons: p,n,Λ,Σ,Δ… s d b NeutrinosCharge=0 Charge=-1 Charge=-1/3 e μ τ ντ νμ νe Mediator γ Z0 W ± G ?graviton 15

  16. Evolution of the Universe life on earth, 15 billion years molecules 1 billion years form heavy elements 1 million years stars and formed galaxies 300,000 years in stars exist, microwave background atoms 3 minutes radiation form helium fills universe nuclei 1 second formed neutrons and protons - quark "soup" 10 10 s formed matter dominates ? 10 15 deg 10 10 deg Big Bang Big Bang 10 9 deg o 6000 o 4000 o -255 o -270 The Universe began with a “Big Bang” about 15 billion years ago 2005/12/9 物理光耀世界(Ⅱ)-紀念1905物理奇蹟年的一百週年 16

  17. Discovery of Parity Violation ne Co60 B field e- C.S. WU In 1957 Madame Wu measured the asymmetry in the beta decay rate of Co60 and found parity was maximally violated 17

More Related